Naiads (Water Nymphs; Waterweeds)

Naiads are slender, narrow-leaved plants that grow completely under water and are rooted to the bottom. The leaves are slender, have finely toothed edges, and occur in pairs or whorls, with each leaf base swollen to form a sheath around the stem. There are tiny greenish flowers at the leaf bases.

Four species of naiads have been recorded in Missouri. The most common is southern naiad (N. guadalupensis), a native species that forms large mats and is sometimes encrusted with lime. Brittle naiad (N. minor), an introduced species, is expanding its range and is expected to become more widespread. Its leaves curve backward during the growing season and have teeth along the edge that are visible without magnification.

Similar species: Several other plants, including some of the narrow-leaved pondweeds. Naiads, however, never have broad, floating leaves or conspicuous flowers or seed heads.

Habitat and conservation:

Submerged aquatics in lakes, ponds, and other calm or slow-moving waters. Some naiads, especially southern naiad, can grow so rapidly they become nuisances. Brittle naiad, native to Europe, was found in the eastern United States in the 1930s. It is spreading quickly, apparently via migrating waterfowl. It was first recorded in Missouri in 1990 and will likely become more widespread. Meanwhile, northern naiad (N. flexilis) is sensitive to pollution and water quality changes and is declining.

Distribution in Missouri:

Statewide.

Human connections:

Naiads and other humble aquatic plants are important parts of the aquatic ecosystem. They help to give us good water quality, fine fishing and boating, attractive landscapes, and all the industry and economic perks that come with such treasures.

Ecosystem connections:

Naiads are an important food for waterfowl, which eat the seeds. As with other submerged aquatics, naiads provide shelter for young fish and other aquatic organisms.

Related Information

Other Content You May Like

Water smartweed can live submerged in water, or on wet banks or other soggy ground, yet it can also live in merely moist areas. The stems often sprawl as they grow, taking root at the swollen nodes. The small, pink flowers develop in long, erect clusters.

Spring branches and streams in the Ozarks are decorated with large colonies of these plants, which can grow like thick green garlands in the water. It has a long history of use as a salad green, and it is cultivated to sell to gourmet cooks. If you collect watercress from the wild, make sure to wash it thoroughly.

Like many of its relatives in the mustard family, spring cress has a bitter or pungent flavor, similar to horseradish. It is sometimes used as a condiment and in salads. Or you could just enjoy the pretty white flowers!

American water willow is common on gravel bars and other stream banks throughout much of Missouri. The dense colonies of emergent stems have leaves like a willow’s, but the two-lipped flowers resemble little orchids.

Hydrilla is probably the worst submersed aquatic weed in America. It harms aquatic communities in small ponds, lakes, and rivers. It hurts our economy by hindering fishing and other recreational uses in large reservoirs. Learn about it and prevent its spread.

Regs and Areas

Shortened URL

Permalink for this page:
http://mdc.mo.gov/node/23361

Serving Nature and You

MDC protects and manages Missouri's fish, forest, and wildlife resources. We also facilitate your participation in resource-management activities, and we provide opportunities for you to use, enjoy and learn about nature. Read more about our mission.